Loading ...
Sorry, an error occurred while loading the content.

PPLetterpress] printing images on polymer plates

Expand Messages
  • livres@artnet.net
    Hello and welcome. tI do pretty much the same, there are a couple books to be considered -I asume that you know and have all or most of the standard ones. This
    Message 1 of 4 , Jul 6, 2006
    • 0 Attachment
      Hello and welcome.

      tI do pretty much the same,

      there are a couple books to be considered -I asume that you know and
      have all or most of the standard ones. This concerns printmaking only.

      Printmaking with Photopolymerplates by Dianne Longley
      Printmaking in the Sun by Dan Welden

      Digital Printmaking by George Whale is more on File prep for Digital
      printes, but instead you can rip and make Film.

      cheers,

      Charles
    • Elizabeth Gross
      Charles, Ludwig et al: Sorry about sending in that note before I had written anything. I do know Printmaking in the Sun. I believe that it focuses on intaglio
      Message 2 of 4 , Jul 9, 2006
      • 0 Attachment
        Charles, Ludwig et al:

        Sorry about sending in that note before I had written anything.

        I do know Printmaking in the Sun. I believe that it focuses on intaglio
        polymer plates. I don't know the Dianne Longley book. Is it about printing
        images for intaglio, letterpress, both?

        What do you print? intaglio?
        Do you use a dove screen or some other sort of mezzotint screen along with
        exposing plates through positives?

        My background is in hand stone and plate lithography. Here I am interested
        in printing images in letterpress, not intaglio. I have used Pictorico to
        make positive transparencies for photo litho plates. The Pictorico seems
        as though it will not be dense enough when I print it, but the plates come
        out quite well. What is best is that there is no strong evidence of a dot
        because of the way Pictorico holds the ink.

        Even if I do get film printed, if I am starting from a wash drawing, I am
        thinking that I can scan it and then output it with a fairly low
        resolution letting the Pictorico take care of the dots. I understand the
        halftone priciple. It seems to me that since letterpress is either on or
        off, not like intalgio where there is shallow and deeper lines of ink,
        that the main issue is whether the polymer plate can hold the detail. So
        that leads me back to the DPI of the digital image. In plate litho it is
        about 133 dpi that works best. So for letterpress is the limit the polymer
        and what can be washed out cleanly after exposure, or is the limit how
        much detail can be maintained with the rollers and ink. (That is being
        hard with the magnesium photo engraving I have been working on.)

        Any more thoughts would be appreciated.

        Regards,
        Liz Gross




        PPLetterpress] printing images on polymer plates
        Posted by: "livres@..." livres@... bookman90035
        Thu Jul 6, 2006 2:45 pm (PST)


        Hello and welcome.

        tI do pretty much the same,

        there are a couple books to be considered -I asume that you know and
        have all or most of the standard ones. This concerns printmaking only.

        Printmaking with Photopolymerplates by Dianne Longley
        Printmaking in the Sun by Dan Welden

        Digital Printmaking by George Whale is more on File prep for Digital
        printes, but instead you can rip and make Film.

        cheers,

        Charles


        Elizabeth Ann Gross
        Deer Tree Press
        eahalegross@...

        __________________________________________________
        Do You Yahoo!?
        Tired of spam? Yahoo! Mail has the best spam protection around
        http://mail.yahoo.com
      • Gerald Lange
        Liz Photopolymer plates processed via an industry standard machine are generally fairly uniform in their quality. Formulas (exposure and washout) can be
        Message 3 of 4 , Jul 9, 2006
        • 0 Attachment
          Liz

          Photopolymer plates processed via an industry standard machine are
          generally fairly uniform in their quality. Formulas (exposure and
          washout) can be adjusted this way and that per a specific job, but
          basically you end up with a tool (with some variables dependent upon the
          type of plate and/or base you are using). Once you've got that in hand,
          it really is the roller adjustments, the packing and makeready, and the
          ink, (basically the presswork) that determine how it will all come out.

          Photopolymer is quite a better printing surface than magnesium as long
          as you control the variables.

          Gerald
          http://BielerPress.blogspot.com





          > So for letterpress is the limit the polymer
          > and what can be washed out cleanly after exposure, or is the limit how
          > much detail can be maintained with the rollers and ink. (That is being
          > hard with the magnesium photo engraving I have been working on.)
          >
          > Any more thoughts would be appreciated.
          >
          > Regards,
          > Liz Gross
          >
          >
          >
        • Ludwig M. Solzen
          Liz et al. It seems there is some confusion regarding proper terminology of resolution and dpi. Resolution is the quality of an image, including its sharpness,
          Message 4 of 4 , Jul 10, 2006
          • 0 Attachment
            Liz et al.

            It seems there is some confusion regarding proper terminology of resolution
            and dpi.

            Resolution is the quality of an image, including its sharpness, amount of
            detail and contrast, whether that be in print or as a digital image. The
            higher one wants the quality of an image to be, the higher its resolution
            should be. There is of course no need, to have more quality (and
            consequently store and process more data on your hard disk), than your
            output process allows for. Depending from the nature of an image and the way
            by which it is processed, resolution is expressed as follows:

            ppi (picture elements or pixels per inch): the resolution of a digital image
            and the devices that acquire them, such as digital cameras and scanners. For
            conventional offset lithography 300 ppi is the standard;

            dpi (raster elements or dots per inch): the resolution of the output device,
            such as a laser printer or an image setter. The higher the resolution, the
            more sharper outlines and bigger tonal range one gets. 600 dpi is a standard
            for desktop lasers, 1200 dpi is a minimum for lettering and 2400 or more dpi
            is for images;

            lpi (lines per inch): the resolution of the halftone screen used to convert
            a digital continuous tone image into a binary pattern of dots, put on a
            line, so that it can be printed by an analogous printing process. One such
            screen dot is made up from several raster elements/dots, so that the dpi
            needs always be bigger than the lpi. With stochastic screening there's no
            use to speak of lines per inch, since there are no regularly repeating
            lines. Here the fineness of the reproducible grain (the raster element of
            the output device) is decisive for the resolution. With a 2400 dpi, you get
            approximately a grain of 10 µm, which in print equals a 220 lpi line screen.

            If you need an image to be printed at say 150 lpi, the resolution of your
            digital image should be about two times larger: 300 ppi. The output device
            should have at least 2400 dpi, for one screen dot is made from 16 raster
            elements.

            If you refer to the ideal resolution for letterpress, you should ask for
            lines per inch (lpi), not dpi resolution. Traditionally 60–80 lpi was used
            for newspapers, with very coarse line screens, because of the low quality
            newsprint paper and the printing speed. With the finest coated papers,
            experienced letterpress printers ware able to catch up with 160 lpi. 133 lpi
            was a long time standard for offset litho, but nowadays most printers use
            150 lpi, some 200 or 220 lpi.

            So, let's assume every one of us should be able to print a 100 lpi halftone
            letterpress, our digital images should have a resolution of at least 200
            ppi, and the film setter one of 1600 dpi. In regard to offset printed
            images, 100 lpi is quite coarse, so I myself prefer no to print halftones
            letterpress, and if I do, I use a stochastic screen, to compensate for the
            otherwise much too obviously repeating line pattern.

            Ludwig
          Your message has been successfully submitted and would be delivered to recipients shortly.